Relative contribution of solar radiation and temperature in enhanced temperature-index melt models from a case study at Glacier de Saint-Sorlin, France

Abstract

AbstractA large set of ice ablation data from a glacier in the French Alps is used to investigate the sensitivity of ice melting to solar radiation and temperature. The data come from 7 years of observations on a small network of 16 stakes set up on Glacier de Saint-Sorlin. The high spatial variability of ice ablation is shown to be strongly dependent on potential solar radiation. On the other hand, temporal variations are highly correlated with air temperatures measured both at a nearby and at a remote meteorological station, but poorly correlated with incoming shortwave radiation measured at an automatic weather station located close to the glacier terminus. Spatial variations of ice ablation therefore appear to be mainly driven by potential solar radiation, while temporal variations are driven by temperature. This result suggests that minimizing the influence of temperature in an enhanced temperature-index melt model may compromise the model’s ability to simulate interannual changes in melt. These new results may help to improve the calibration, and thus the performance, of these empirical melt models used for long-term simulations of glacier mass balances.